Test mapcat

[E-A-Griffin]

Addresses comments in #762 (comment) for @gavlooth 's work; fixes/closes #354 (comment)

[E-A-Griffin]

@jeaye on the local cljs repls I have I get an error for (mapcat identity (range 2)) any idea why the CI suite gets a different result?

[jeaye]

(mapcat identity (range 2))

Could be node vs browser JS? What if you run the CLJS tests locally?

[jeaye]

I get the same in a CLJS browser REPL.

[E-A-Griffin]

Same thing locally, I wonder if it has something to do with the transpilation

[E-A-Griffin]

clojure.core-test.mapcat> (emma-test)

FAIL in (emma-test) (:1:37)
x
expected: (thrown? :default (mapcat identity (range 2)))
  actual: nil

Okay reproduced it with cider, I'll look into this tonight

[E-A-Griffin]

(deftest emma-test2 (testing "y" (is (nil? (mapcat identity (range 2))))))
;; => #'clojure.core-test.mapcat/emma-test2
cljs.user> (in-ns 'clojure.core-test.mapcat)
;; => nil
clojure.core-test.mapcat> (emma-test2)

FAIL in (emma-test2) (:1:38)
y
expected: (nil? (mapcat identity (range 2)))

ERROR in (emma-test2) (:1:38)
y
expected: (nil? (mapcat identity (range 2)))
  actual: #object[Error Error: 0 is not ISeqable]
;; => nil

So it looks like there's a certain class of error that isn't being caught for some reason?

[E-A-Griffin]

@jeaye it's a quirk with cljs's laziness, since the lazy-seq isn't realized yet, nothing is thrown, easy fix for this issue but something to keep in mind for sure

[E-A-Griffin]

cider doesn't work on this project without this, @jeaye if you want me to do this in a separate PR that's fine but I think we should have it

[jeaye]

Nice work, Emma and Christos!